This invention relates to a coiler apparatus of the type used to form flat coils of yarn during various types of yarn processing. In this application the coiler is described in conjunction with a continuous yarn dyeing system, such as long and short space dyeing and solid shade dyeing. The coiler is used to place the yarn in a relatively compact, uniform array which can be processed with uniform applications of dye and/or steam. The yarn must be coiled in such a manner as to permit rewinding of the yarn from coil form back onto a suitable yarn package without tangling or knotting.
Prior art coilers generally form either round or substantially round coils which do not allow uniform density of the yarn on as deposited on the conveyor. This can result in a lack of homogeneous yarn retraction during thermal treatment. Round loops or coils present a much higher overall density of material on the sides than at the center, resulting in substantially different characteristics being imparted to the yarn residing on the sides of the coils. This can result in variations in dyeing shades in yarn.
Prior art devices which disclose formation of oval coils or loops are relatively complicated and present other processing problems. An example of such a device is shown in U.S. Pat. No. 5,024,390.